United, ANA find wire problems on 787 transmitters

July 27, 2013

Two airlines disclosed issues with the wiring on their Boeing 787's emergency transmitters, the same part of the plane that is getting close scrutiny after a parked jet burned earlier this month.

United Airlines said Friday that it found a pinched wire during an inspection of one of its six 787s. Earlier, Japan's All Nippon Airways found damage to wiring on two Boeing 787 locater beacons. It flies 20 of the jets.

The inspections were mandated by the Federal Aviation Administration for U.S. airlines after the tail of an Ethiopian Airlines 787 caught fire while parked at London's Heathrow airport earlier this month. U.K. investigators said the only thing in the tail section with enough power to fuel a fire like that was the emergency transmitter.

That's a metal-cased, battery-operated radio the size of a loaf of bread that activates in a crash to help rescuers find a plane.

The FAA said last week it would require U.S. airlines to look for "proper wire routing and any signs of wire damage or pinching," and to check the transmitter's battery compartment for signs of heating or moisture. It issued a formal order on Thursday. The European Aviation Safety Agency issued its own order on Friday.

A wire could short-circuit if it's pinched by metal and the metal cuts through the wire's insulation, exposing the part that carries electricity.

United Continental Holdings Inc. spokesman Christen David said the transmitter with the pinched wire was removed and sent to its maker, Honeywell International Inc. Inspections were carried out without any impact on United's flight schedule, she said. That transmitter was replaced, and United has working transmitters on all of its 787s, she said.

Spokesmen for Honeywell International Inc. and Boeing Co. both declined to comment, citing the ongoing investigation.

So far, the FAA and European orders have only covered 787s. That's Boeing's newest plane, and only 68 have been delivered so far. But those particular transmitters are used on far more planes - U.K. investigators said they've been installed on some 6,000 aircraft.